Transition-metal-catalyzed electrosynthesis remains challenging in preventing metal deposition under direct current (DC) conditions. Compared to DC electrolysis, alternating current (AC) electrolysis features polarity reversal and periodic variation, which shows great potential in recirculated metal species. However, the catalyst self-circulation and electricity consumption has impeded the development of AC electrolysis. Herein, we highlight two novel and practical advances of AC electrolysis in addressing this long-standing challenge, and emphasize reaction development, mechanistic investigation and future challenges.